The invention relates to an apparatus or method for processing, more particularly for collating, sheet or flat material into packs, such as cubic piles or stacks. The layers then form in the stack flat faces throughout on all sides and adjoin each other in an inclined direction or vertically. Provided in the pile may be differingly sized layers of material. A larger or first layer is a support layer, such as a pallet, and smaller or second layers are individual sheets of paper or the like. The latter are collated in common with a wrapping or the like to form a substack, such as a ream of paper. All edge faces of each stack layer are set back relative to all corresponding edge faces parallel thereto of the support layer in the pile. So they are protected from impact during shipping by the protruding support layerxe2x80x94termed pallet in the following.
Precisely aligning the layers, namely the pallet and the stack layersxe2x80x94termed reams in the followingxe2x80x94relative to each other is difficult when they need to be collated at high speed before being delivered as unit sets. If the layers are simply aligned be being moved on a conveyor against a stop they may assume positions rotated out of place relative to each other, namely skew instead of in line relative to each other. If the stack layers are shifted relative to each other on completion of piling, damage may occur due to the layers resting on each other under a high face pressure or under the weight superposed.
An object is to provide an apparatus or a method which avoids the disadvantages of known configurations or as described. Another object is to ensure a precise alignment of the layers after placement on a table top or on the stack or the like. A still further object is to permit fully automatic collation or stacking of the layers.
According to the invention means are provided for primarily depositing layers, pallet and/or reams, on a table top and for subsequently aligning a predetermined number of stack layers parallel to the table top, this number being any between one and three or five. Alignment is achieved in first and second directions parallel to the table top, the second direction being oriented at right angles to the first direction. In the case of rectangularly bounded layers each of the directions is located at right angles as well as parallel to the edge faces of these layers. The means firstly align the pallet slidingly on the table top. Thereafter several reams are placed on the pallet and on each other before then being aligned in common on the pallet as well as on each other slidingly. Thereby all edge faces associated with each other of these reams are located in the same plane as well as set back relative to the corresponding edge faces of the pallet by the same distances. For instance, the center axes at right angles to the planes of all layers may be coaxial in the finished or finally aligned condition. It is an advantage to initially deposit the ream offset from its final alignment, by prealigning it to one side before then shifting it into final alignment.
As aligning members the same stops or pushers may be used both for aligning the pallet and subsequently for aligning the reams. For prealignment it is of advantage to provide a separate stop, such as a motion stop respective a separate pusher, such as a conveyor. The latter transports the reams from a zone remote from the stacking zone above the stack, aligning them thereby, before transferring them in this prealigned condition to the table. The aligning stops may be moved in a gripper action towards each other as well as towards the edge faces of the layers, more particularly exclusively linearly or parallel to the table plane. In this arrangement one of the two stops in each case may be positively locked in its stopping position by another stop to ensure precise positioning with speedy adjustment.
Instead of being desposited on a pallet the reams may also be directly placed on the table top, enabling nonpalletized piles to be formed. The stack layers can be then positionally interlocked by a common wrapping, for example, a full covering packaging of paper, carton or the like. The piling table provides a lift so that it can be lowered during piling by the thickness of each layer to ensure that the same transfer conditions exist for each such layer. Although the stops could be mounted on the piling table and adjustable relative thereto transversely to the table plane namely height-adjustable, they are preferably positioned in stationary fixtures or mounts of the stationary base frame of the apparatus. Thereby their spacing from the table plane changes with the height-adjustment of the stacking table. Accordingly, the stops can always be located to be effective in the region of the topmost layers whilst no longer being able to come into contact with the layers already aligned therebelow.
It is of advantage to feed the pallet to the piling table in one direction, for example in the cited second direction, whilst the reams are fed in a direction oriented at right angles, for example, in the cited first direction. Thereby an intersecting feed is achieved when seen in plan view on the table plane. At the stationary point of intersection stacking and alignment of all first and second layers accurs, after which the stack is removed co-directional with the prior feeding of the pallet.
Feeding and aligning of each of the layers may be implemented in accordance with European Patent Application 97121516.5 (date of application: Dec. 6, 1997), reference being made to the features and affects thereof for incorporating them into the present invention.